/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package org.apache.hadoop.yarn.ipc;

import java.io.IOException;
import java.net.InetSocketAddress;

import org.apache.hadoop.ipc.Server;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.ipc.AvroSpecificRpcEngine;
import org.apache.hadoop.ipc.RPC;
import org.apache.hadoop.security.token.SecretManager;
import org.apache.hadoop.security.token.TokenIdentifier;
import org.apache.hadoop.yarn.YarnException;

/**
 * This uses Hadoop RPC. Uses a tunnel AvroSpecificRpcEngine over 
 * Hadoop connection.
 * This does not give cross-language wire compatibility, since the Hadoop 
 * RPC wire format is non-standard, but it does permit use of Avro's protocol 
 * versioning features for inter-Java RPCs.
 */
public class HadoopYarnRPC extends YarnRPC {

  private static final Log LOG = LogFactory.getLog(HadoopYarnRPC.class);

  @Override
  public Object getProxy(Class protocol, InetSocketAddress addr,
      Configuration conf) {
    LOG.info("Creating a HadoopYarnRpc proxy for protocol " + protocol);
    RPC.setProtocolEngine(conf, protocol, AvroSpecificRpcEngine.class);
    try {
      return RPC.getProxy(protocol, 1, addr, conf);
    } catch (IOException e) {
      throw new YarnException(e);
    }
  }

  @Override
  public Server getServer(Class protocol, Object instance,
      InetSocketAddress addr, Configuration conf,
      SecretManager<? extends TokenIdentifier> secretManager,
      int numHandlers) {
    LOG.info("Creating a HadoopYarnRpc server for protocol " + protocol + 
        " with " + numHandlers + " handlers");
    RPC.setProtocolEngine(conf, protocol, AvroSpecificRpcEngine.class);
    final RPC.Server hadoopServer;
    try {
      hadoopServer = RPC.getServer(protocol, instance, addr.getHostName(), 
          addr.getPort(), numHandlers, false, conf, secretManager);
    } catch (IOException e) {
      throw new YarnException(e);
    }
    return hadoopServer;
  }

}
